Comparison of the median (range) for the perceived maximum benefit after injection (−1 to +3) and the current level of benefit (−1 to +3) between the accurately and inaccurately injected subgroups
| Accurate | Inaccurate | P value | |
| Maximum benefit | 2 (1 to 3) | 1 (0 to 3) | 0.034 |
| Current benefit | 2 (0 to 3) | 1 (0 to 3) | 0.07 |